feat(s3-request-presigner): add getSignedUrl() from client and commands

[AllanZhengYP]

Add getSignedUrl() to get signed url from client and command. The existing presigning method using S3RequestPresigner only takes existing HTTP request. It has 2 problems:

1. Users need to write verbose code to generate an S3 presigned URL. Before calling S3RequestPresigner they usually need to use @aws-sdk/util-create-request dependency to get the HTTP request from command and client.
2. Doesn't support presigning with overriden signing region and signing serivce which comes from handle execution context. For example, is user has a request that needs to be signed with region inferred from input parameter("useArnRegion"), the logic will be too complexed.

getSignedUrl also provide a familiar method compared to V2 SDK.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov-commenter]

Codecov Report

Merging #1454 into master will increase coverage by 0.02%.
The diff coverage is 97.22%.

@@            Coverage Diff             @@
##           master    #1454      +/-   ##
==========================================
+ Coverage   79.77%   79.80%   +0.02%     
==========================================
  Files         297      298       +1     
  Lines       11480    11502      +22     
  Branches     2470     2475       +5     
==========================================
+ Hits         9158     9179      +21     
- Misses       2322     2323       +1     

Impacted Files	Coverage Δ
packages/s3-request-presigner/src/getSignedUrl.ts	95.45% <95.45%> (ø)
packages/s3-request-presigner/src/presigner.ts	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 8a0febd...65ace72. Read the comment docs.

[alexforsyth]

very minor comments. LGTM!

[trivikr]

LGTM, just one nit

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs and link to relevant comments in this thread.